OBJECTIVE: The objective of this funding is to investigate the possible mechanisms of modification of tumor growth by portacaval shunt. APPROACH: We have proposed to follow two approaches to the problem. The first approach is to investigate the effect of investigation of portacaval shunt on tumors of different types and tumors in different locations. The second objective is to investigate the possible influence of extracts, specifically, the liver from a rat with portacaval shunt on the growth of tumor both in vivo and in vitro.